That's a tough one to answer. Since not everyone sees every page of every issue of the paper, it takes numerous insertions to gain enough frequency with a specific target audience for a message to penetrate. The actual frequency you need will also depend on the complexity of your message and what's being sold.
A Note From The Editor
Free Webinar: How to Use Customer Service as a Marketing Tool
Tune in October 12th as we highlight some of the best tools to create brand loyalty by leveraging your customer experience data.